Statistics Fundamentals Final Milestone
You passed this Milestone
22 questions were answered correctly.
3 questions were answered incorrectly.
1
Which of these random samples represents a representative sample
of the systolic blood pressure of all patients in a hospital?
The systolic blood pressure of 50 children admitted in the hospital.
The systolic blood pressure of 50 patients in the hospital.
The systolic blood pressure of 50 employees in the hospital.
The systolic blood pressure of 50 patients in the neurology department.
RATIONALE
For a sample to be representative it needs to look like the entire set of interest. To look
like all patients in the hospital, they should be randomly sampled from the entire
population not simply the neurology department or children. Employees are not a part
of the population of interest.
CONCEPT
Random & Probability Sampling
2
Rachel recorded the number of calls she made at work during the week:
Day Calls
Monday 18
Tuesday 14
Wednesday 24
Thursday 16
She expected to make 18 calls each day. To answer whether the number of
calls follows a uniform distribution, a chi-square test for goodness of fit
should be performed. (alpha = 0.10)
, What is the chi-squared test statistic? Answers are rounded to the
nearest hundredth.
3.11
1.52
4.61
3.27
RATIONALE
Using the chi-square formula we can note the test statistic is
CONCEPT
Chi-Square Test for Goodness-of-Fit
3
A poll conducted a week before the school election to the student council
showed that Janice would win with 63% of the vote. The margin of error was
14%.
If Janice needs to receive at least half the votes to win the election,
can we be confident of Janice's victory?
Yes, because the poll stated that she will win with 63% of the vote.
No, because she could receive as low as 49% of the vote.
No, because she could receive as low as 14% of the vote.
Yes, because she could receive as much as 77% of the vote.
RATIONALE
Recall for a confidence interval, we take the point estimate +/- margin of error. Using
this framework we take the point estimate of 63%, then add and subtract the margin of
error, 14%.
, This gives us a CI of 49% to 77%.
Given that you need to have at least 50% of the vote and we are confident that 49% is
possible given our CI, we are not confident that Janice will win.
CONCEPT
Margin of Error
4
There is a 30% chance of rain tomorrow.
What are the odds in favor of it raining?
3:7
3:10
10:3
7:3
RATIONALE
Recall that we if we have a probability " ", we can formally express odds as " ".
So if the probability is 30%, or 30/100 in fraction form, then we can express odds as:
CONCEPT
Odds
5
This scatterplot shows the performance of an electric motor using the
variables speed of rotation and voltage.
You passed this Milestone
22 questions were answered correctly.
3 questions were answered incorrectly.
1
Which of these random samples represents a representative sample
of the systolic blood pressure of all patients in a hospital?
The systolic blood pressure of 50 children admitted in the hospital.
The systolic blood pressure of 50 patients in the hospital.
The systolic blood pressure of 50 employees in the hospital.
The systolic blood pressure of 50 patients in the neurology department.
RATIONALE
For a sample to be representative it needs to look like the entire set of interest. To look
like all patients in the hospital, they should be randomly sampled from the entire
population not simply the neurology department or children. Employees are not a part
of the population of interest.
CONCEPT
Random & Probability Sampling
2
Rachel recorded the number of calls she made at work during the week:
Day Calls
Monday 18
Tuesday 14
Wednesday 24
Thursday 16
She expected to make 18 calls each day. To answer whether the number of
calls follows a uniform distribution, a chi-square test for goodness of fit
should be performed. (alpha = 0.10)
, What is the chi-squared test statistic? Answers are rounded to the
nearest hundredth.
3.11
1.52
4.61
3.27
RATIONALE
Using the chi-square formula we can note the test statistic is
CONCEPT
Chi-Square Test for Goodness-of-Fit
3
A poll conducted a week before the school election to the student council
showed that Janice would win with 63% of the vote. The margin of error was
14%.
If Janice needs to receive at least half the votes to win the election,
can we be confident of Janice's victory?
Yes, because the poll stated that she will win with 63% of the vote.
No, because she could receive as low as 49% of the vote.
No, because she could receive as low as 14% of the vote.
Yes, because she could receive as much as 77% of the vote.
RATIONALE
Recall for a confidence interval, we take the point estimate +/- margin of error. Using
this framework we take the point estimate of 63%, then add and subtract the margin of
error, 14%.
, This gives us a CI of 49% to 77%.
Given that you need to have at least 50% of the vote and we are confident that 49% is
possible given our CI, we are not confident that Janice will win.
CONCEPT
Margin of Error
4
There is a 30% chance of rain tomorrow.
What are the odds in favor of it raining?
3:7
3:10
10:3
7:3
RATIONALE
Recall that we if we have a probability " ", we can formally express odds as " ".
So if the probability is 30%, or 30/100 in fraction form, then we can express odds as:
CONCEPT
Odds
5
This scatterplot shows the performance of an electric motor using the
variables speed of rotation and voltage.
